Somewhere I got to a webpage that recommended your site, so here I am.
I have no professional certifications, accreditations or employment. Long ago I was a HVAC tech and know repair. I have no installation experience. I have re-hab'd existing residential and small commercial units and air handlers.
Not so long ago, I got an estimate for a refit hvac in a 800sqft house from a retailers everyone would know if I said. The ac is 2.5 ton and the natural gas furnace was 80Kbtu. The estimate was only verbal and I had 3 options. The $ options. Variable fan speeds, to two speed fan to single speed fan. Variable flame to fixed output flame and so forth.
I have a few ideas and since I pay, I figure it should count.
I like split-mini's. They are so quiet and have a heat pump option. I'd need several and the cost is up to $ pretty fast. Many in Asia, and I liked them. Few in the US though. I like the zone idea so the office can stay cool without cooling the whole home.
Hi-V in an idea. Old houses seem to like this. Needs mufflers to be quiet and really nice air distribution in the room. Add a heat element, natural gas flame or HW boiler and the cost is somewhat over $.
Too much for an intro? Hope I'm on-topic enuf.
Welcome to the site.
Please post questions in the residential area, you will get more answers there.
Might want to edit prices out of your post as they are against the rules.
Your post edit ability is limited to 15 minutes. I removed them for you. Enjoy our site.